The present invention is an extension of the technology disclosed in U.S. Pat. No. 4,984,276, which teaches the use of digital processors having digital waveguide networks for digital reverberation and for synthesis of musical sounds such as those associated with reed and string instruments.
The present invention falls into the class of synthesizers sometimes known as source/filter models because such synthesizers take into account the acoustic mechanisms that produce speech. In particular, the present invention provides a practical mechanism for explicitly modeling the shape of the vocal tract. Speech synthesis is accomplished by filtering glottal source signals with a set of digital waveguides set up to represent the time varying shape of the vocal tract associated with a specified output speech signal (such as a specified set of spoken words).